Rene 108 superalloy is becoming a desired material of choice for buckets, nozzles, and shrouds in advanced gas turbines. Rene 108 has excellent mechanical and oxidation properties at elevated temperatures. However Rene 108 has poor weldability and is one of the hardest to weld materials in the superalloy category. Welding on Rene 108 using any traditional arc welding procedures results in a significant cracking in the weld metal and base metal heat affected zone.
Laser welding or laser hybrid welding of Rene 108 generates undesirable cracks along the weld line. Generally, the cracks produced from laser welding are perpendicular to the welding joint. Undesirable cracks along the weld line lead to unacceptable welds.
Therefore, a welding system and apparatus and a method of welding that do not suffer from the above drawbacks are desirable in the art.